1. Field of the Invention
This invention relates generally to earth digging tools, and more particularly to a post hole digging tool having a semi-cylindrical blade, an elongate handle, and a pair of hand grips at the top end of the handle which is rotatable about a central longitudinal axis and can be disassembled and stored or transported in a compact configuration. 2. Brief Description of the Prior Art
When erecting or repairing a fence, the digging of the holes for the fence posts is a laborious and time consuming task. Various digging tools have been used in the past to accomplish the digging operation.
Often a common wooden handle shovel is used, but the hole dug by this method is generally conical-shaped and much larger than necessary for the post. The larger than necessary hole makes it difficult to correctly position the post and even if initially positioned correctly, the post will often shift or lean from the true vertical position during or after the concrete or other fill material is placed in the hole. This method is time consuming and requires a great deal of bending and lifting and sometimes results in back strain and hand blisters. Another disadvantage is that the shovel cannot be disassembled and will not easily fit in the trunk of an automobile.
Another common tool for digging post holes is a tool which has a pair of opposed curved blades pivotally connected at their top ends and a pair of elongate wooden handles which extend upwardly from the connection. The tool operates in a scissors fashion. To use this tool, the handles are held together to position the blades in vertically opposed relation and the tool is held above the hole location and then forcefully plunged into the ground. Then the handles are pulled outwardly apart from one another causing the blades to pinch together and then the soil pinched between the blades is lifted out of the ground while holding the handles apart. This method is more efficient than digging with a shovel and produces a smaller hole. However, this method is also time consuming and requires a great deal of bending and lifting in addition to the repeated pulling the handles apart and pressing them together against the resistance of the soil plug and often results in back strain and hand blisters. This tool also cannot be disassembled and will not easily fit in the trunk of an automobile.
Others have attempted to solve these problems and there are several patents which disclose various tools and implements for digging holes.
Kemmerer, U.S. Pat. No. 814,850 discloses a tool for digging holes comprising a unitary shank having a crescent-shaped blade formed at the bottom end and a cross-bar attached at the top end. The crescent-shaped blade is open at both ends. The longitudinal edges of the blade are sharpened and the lower end of the blade is tapered to a point. The handle and blade of this tool are integrally formed and cannot be disassembled.
Gillogy, U.S. Pat. No. 1,829,002 discloses a ball shaper having a replaceable flat-bottomed, semi-circular blade open at both ends with longitudinal edges which subtend slightly more than 180.degree.. A pair of semi-circular reinforcing bands are secured to the inside and outside surfaces of the upper edge of the blade. An elongate handle secured to the back part of the blade extends upwardly parallel to, and offset from, the longitudinal axis of the blade and has a D-shaped hand grip at its upper end. The offset handle allows the tool to be forced into the ground concentric with the trunk of a tree or plant and it is repeatedly forced into the ground at circumferentially spaced locations to complete a circle pattern surrounding the tree or shrub and cutting the small roots. The construction of this tool makes it impossible to rotate the blade after it has been forced into the ground.
Pooler, U.S. Pat. No. 1,470,284 discloses a hand-held digger implement for digging up weeds which is operated by the hand and fingers of the user. The digger comprises a hollow tube member which is cut-away throughout its major portion to form a semi-cylindrical blade at the lower portion and a tubular upper portion. A wooden handle member has an elongate shank which is slidably received in the tubular portion of the blade. The shank of the handle and the tube are held together by a wedge-shaped pin passing transversly through the tube and shank of the handle. In operation, the blade is thrust into the ground near the root of the weed and given a slight turn, after which it is withdrawn by placing the fingers in engagement with the wedge pin. This is a hand-held implement similar to a flower trowel and designed for removing the roots of weeds and would not be suitable for use in digging large deep post holes.
The present invention is distinguished over the prior art in general, and these patents in particular by a post hole digging tool having a semi-cylindrical blade member, an elongate handle member, and a pair of hand grip members which can be quickly and easily assembled and disassembled. The blade has a top end wall and a short cylindrical reinforcing ring at its upper end and is semi-circular in transverse cross section. The bottom edge and longitudinal edges of the blade are sharpened to provide soil penetrating surfaces. A threaded collar extends upwardly from the center of the top wall. The handle member is removably connected at its lower end to the collar on the top wall of the blade and extends upwardly in axial alignment with the central axis of the blade and has a tee-shaped portion at its top end. Each hand grip member is removably connected to the lateral ends of the tee-shaped portion and may have an outer covering of resilient material to provide a comfortable gripping surface for the hands of the user and prevent blisters. The longitudinal blade surface is rotatable about the central longitudinal axis of the blade and handle upon turning the hand grip members in clockwise or counterclockwise direction about the handle axis. The blade member, handle member, and hand grip members can be disconnected from one another whereby the tool may be disassembled and stored or transported in a compact configuration.